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Endometriosis

Endometriosis is a disease that can cause pain and infertility in women. It affects over half a million Australian women and over 100 million worldwide. In this article we look at the disease, its epidemiology and treatment, and what is being done to reduce its occurrence and impact in Australia.

What is endometriosis?

The clinical definition of endometriosis is the presence of endometrial-type mucosa outside the uterine cavity. Expressed in simpler terms, endometriosis occurs when tissue is disseminated and forms deposits outside the uterus, where it interferes with normal physiological processes.

Common symptoms of endometriosis are painful periods, painful ovulation, pain during or after intercourse, heavy periods, pelvic pain, fatigue and infertility. Endometriosis is the most common cause of chronic pelvic pain and has an estimated prevalence of 25–40 per cent in infertile women.

Causes of endometriosis

The precise cause of endometriosis remains unknown, but it is generally believed to be an estrogen‐dependent disorder. The evidence for this belief includes observation of reductions in pre‐existing endometriosis after menopause and the growth of endometrial tissue caused by estrogen therapy in animals.

Estrogen and progestogen are key hormonal regulators of cell destruction, growth and renewal in the human endometrium. Women diagnosed with endometriosis are found to have an attenuated response to progesterone, suggesting a genetically determined resistance to this hormone.

Endometriosis shows similarities to several autoimmune diseases in its generation of chronic inflammation and auto-antibodies. Researchers are currently investigating the links between these conditions, with a view to developing both diagnostics and treatment for endometriosis.

There is some evidence that dietary fat intake affects the risk of endometriosis. Researchers analysed 12 years of prospective data, involving 586 153 person-years of follow-up, from the Nurses’ Health Study II. Total fat consumption was not associated with diagnosis of endometriosis, but women in the highest fifth of long-chain omega-3 fatty acid consumption were 22 per cent less likely to be diagnosed than those in the lowest fifth of intake. In addition, those in the highest quintile of trans-unsaturated fat intake were 48 per cent more likely to be diagnosed than those in the lowest fifth. These results suggest that consumption of trans fats from hydrogenated oils is associated with the incidence of endometriosis (in addition to many other deleterious health effects) and should therefore be avoided.

The epidemiology and costs of endometriosis

Worldwide, an estimated one in 10 women – 176 million – suffer from endometriosis. It mostly affects adolescents and reproductive-aged women. Research conducted in 10 countries in 2008–10 showed that women with endometriosis had significantly lower health-related quality of life than women with similar symptoms and no endometriosis. Women with endometriosis lost an average of 10.8 hours of work a week, mainly due to reduced effectiveness while working. This translated into costs per woman per week ranging from US$4 in Nigeria to US$456 in Italy.

Endometriosis affects an estimated 560 000 reproductive-aged Australian women, and costs an estimated $7.7 billion annually. About two thirds of these costs are due to lost productivity, and the remainder, about $2.5 billion, are direct health care costs. To put these figures in context, diabetes – one of the 12 most burdensome chronic conditions in Australia – costs about $1 billion annually in direct health care costs.

Diagnosis

Diagnosis of endometriosis requires a laparoscopy (insertion of a fibre-optic instrument into the abdomen) and a biopsy, performed under a general anaesthetic. A tiny sample of tissue suspected of containing endometriosis is removed and sent for pathological microscopy.

There is commonly a long delay between experience of symptoms of endometriosis and its diagnosis, potentially exacerbating the problem. The 10-nation study referred to earlier found an average diagnostic delay of 6.7 years.

Treatment

No cure for endometriosis exists. Current treatments for endometriosis consist of medications, complementary treatments (physiotherapy, psychology, alternative medicine etc.) and surgery.
Hormonal treatments include the oral contraceptive pill and progestogens (one of the two main female hormones), taken as tablets or injections, or by means of a rod implanted subcutaneously or using an intra-uterine device. Non-hormonal medications, such as paracetamol and non-steroidal anti-inflammatory drugs (NSAIDS), are used to relieve the pain associated with endometriosis but do not affect the condition itself.

Physiotherapy using neuromuscular electrical stimulation (NMES) has shown some benefit for the treatment of pain associated with endometriosis. Researchers gave 83 patients 30 minutes of NMES therapy three times a week for 10 weeks, while 71 subjects in the control group received no therapy. NMES produced significantly better outcomes in terms of reducing self-reported pain and severity of endometriosis symptoms and improving quality of life.

Surgery is a common form of management, but symptoms recur in 20 to 40 per cent of patients 2–5 years after surgery, and many women require subsequent surgery.

A Cochrane Overview of 17 systematic reviews found moderate-quality evidence that suppressing menstrual cycles with the levonorgestrel-releasing intra-uterine system relieved the pain of endometriosis. In contrast, the Overview found that evidence of a difference in effectiveness between progestogens and placebo was inconsistent and deemed that research to be of low or very low quality. Research on NSAIDS was also deemed inconclusive with respect to symptom relief.

The same Overview reported moderate-quality evidence that laparoscopic surgery relieved pain significantly better than diagnostic laparoscopy (that is, no treatment, and also improved rates of pregnancy and live births).

If autoimmunity proves to be a factor in endometriosis, immunomodulatory therapy for autoimmune disease might eventually be a useful treatment.

Australia’s National Action Plan for Endometriosis

On 26 July 2018, the Australian Government released Australia’s first National Action Plan for Endometriosis. Its objectives, clustered under three priorities – awareness and education; clinical management and care; and research – are as follows.

Awareness and education

  • Improved public understanding and health literacy through targeted education initiatives and visible, widespread, public awareness campaigns with particular regard to vulnerable and at-risk population groups.
  • Patients, families, partners and their carers are empowered, well-informed, active decision-makers and participants in their own health care with streamlined access to a broad range of resources, including self-education and self-management tools.
  • Healthcare professionals, educators and employers are well-informed about endometriosis and its significant impacts, take women’s pain seriously and provide appropriate care and support for all people with endometriosis.

Clinical management and care

  • Healthcare professionals are supported to deliver best-practice, nationally consistent clinical management and care of endometriosis and chronic pelvic pain.
  • Early access to endometriosis-specific education, diagnosis, intervention, fertility treatment, pain management options and providers of choice reduces delays at all stages of the care pathway.
  • Affordable and accessible pain management, mental health and psychosocial care options for all patients, including vulnerable population groups, with nationally consistent clinical guidelines, standards and pathways, to aid strong clinical delivery.

Research

  • The gap in quality of life, including social and economic participation, between patients with endometriosis and their peers continues to narrow.
  • Patients benefit from greater understanding of the nature and cause of endometriosis and have access to simpler and less invasive diagnostic tests and treatment options.
  • High-quality research findings are translated and implemented to achieve real-world outcomes, and there is continuing progress towards prevention and the development of a possible cure.

These objectives are to be achieved through 47 specific actions. To ensure the National Action Plan implements these actions and fulfils its objectives, an Implementation Steering Group will facilitate and drive the Plan, and will conduct a five-year review, with 12-month and three-year development checks, to assess progress.

The proposed criteria for the five-year review of progress are:

  • Have nationally endorsed Australian Clinical Care Guidelines been developed, and disseminated throughout the country?
  • Has access to appropriate health care improved for women and girls with endometriosis, including assessment, diagnosis, pain management, psychosocial support and specialist services?
  • Have school menstrual education programs been implemented and embedded, and has students’ knowledge and awareness increased?
  • Do general practitioners, other healthcare professionals, employers and the community throughout Australia demonstrate a base-level increase in understanding of endometriosis?
  • Are optimal care pathways available for patients with endometriosis, from first consultation through to surgical intervention and post-operative care?
  • Has the domestic research program expanded significantly, with a view to meeting international research priorities?

Conclusions

Endometriosis is a debilitating condition that affects hundreds of thousands of Australian women and over 100 million worldwide, and generates substantial health care and economic costs. Treatments exist, but they treat the pain and other symptoms of the disease rather than the cause. Research is progressing on many fronts, with autoimmune pathways holding some promise for therapy. If implemented effectively, Australia’s recently announced National Action Plan for Endometriosis should raise awareness of the condition, reduce the time between onset and diagnosis and improve access to appropriate care, thereby potentially improving treatment outcomes for many women. It will also expand domestic research into methods of prevention and cure.

Further information

More information about endometriosis is available from:

  • About the author: Campbell Aitken
  • Dr Campbell Aitken is a freelance editor and a senior research fellow at the Burnet Institute.

If you would like to write an article for our Talking Points newsletter or In Brief blog, email Cassandra Hamilton (cassandrahamilton@westernalliance.org.au) or call 03 4215 2900.